Sediment Filter Location and more

I have a shallow well that I just got operating correctly, for the most part, but there are some issues.

One issue that I have is some sand/silt upon initial start up. I installed a sediment filter and the irrigation system works well enough that my lawn is green once again. One thing that I have noticed is that my new pressure switch will not always operate, and I have to take it off and clean out the silt that I find. Since I didn't install the filter before the pressure switch, I see myself re-plumbing the output to place the filter before the switch/tank. Can I get confirmation that it is the right thing to do?
I have also noticed that my new check valve (Home Depot-Brass) doesn't always close/seal correctly, allowing the system to loose prime (I blame residual silt). Are there any check valves out there that are better than others? Could I replace the spring with a slightly stiffer one to help seal after shut down? Since I believe I will be re-plumbing the pump output, should I also re-do the input and mount the check-valve in a verticle instead of horizontal direction?
Here's my last issue, the system is for irrigation only, and the sand/silt only appears for a minute or two, if at all, upon pump start up. My thought is to install a new Zone 1 before the sediment filter, and use it as a 3-4 minute "Dump" when it begins pumping. This would allow the sand/silt to be pumped out without the possibility of clogging the filter, which can continue to catch the little stuff while watering. I guess one downside is a stuck open Zone 1 (due to the crap I'm trying to get rid of) and less water for the rest of the Zones. Good idea/bad idea?

If you are using the well exclusively for irrigation, why bother with the tank and pressure switch at all? My thoughts would be to use a pump start relay to power on the pump. This way your sprinkler control clock turns the pump on and off. I normally set a sand separator after the pump and before the tank (if there is one).

If you have sand in your system, You need to set any check valve as vertical as possible. (I know, I know, the least number of fittings between the point and pump) There is a reason that check valves are not allowed for backflow prevention, and it is for the very instance that you are experiencing. The sand and sediment basically jams the action, and freezes the spring. Buying a quality part (read: not from a big box store, from a supply house) may help, but the sand will still be there.

The pump will be used for irrigation, 99.9999% of the time through the sprinkler system. I have two faucets plumbed in so that a hose can also utilize the well water, hence the tank & pressure switch. I do plan on moving the filter immediately outside the pump discharge, prior to the tank/switch.

I guess I will also change the check-valve to a verticle position, should I make the investment in a better valve, or will re-orientation work 99% of the time.

My real hope is that once I make all the changes to prevent sand from being an issue, I will have pumped the sand out and all will be good.